Villar D, Klafke G M, Rodríguez-Durán A, Bossio F, Miller R, Pérez de León A A, Cortés-Vecino J A, Chaparro-Gutiérrez J J
CIBAV Research Group, School of Veterinary Medicine, Faculty of Agrarian Science, Universidad de Antioquia, Medellín, Colombia.
USDA-ARS Cattle Fever Tick Research Laboratory and Veterinary Pest Genomics Center, Edinburg, TX, U.S.A.
Med Vet Entomol. 2020 Mar;34(1):105-115. doi: 10.1111/mve.12418. Epub 2019 Nov 19.
Intensive use of chemical acaricides for the control of cattle ticks (Rhipicephalus microplus) has led to the development of multiple acaricide resistance in Colombia. The present study aimed to characterize, using toxicological bioassays and molecular biology techniques, the resistance profile of a tick strain isolated from the Arauca state, Northeast Colombia. Commercial acaricides were used in adult immersion tests to determine its in vitro efficacies. Deltamethrin showed very low activity (4-7.3%), a mixture of cypermethrin and chlorpyrifos had intermediate efficacy (64-75.2%), and ethion presented the highest activity (88.5-100%). A colony (Arauquita strain) was established and larval immersion tests confirmed high resistance level to deltamethrin (241-fold) and susceptibility to ivermectin. A quantitative polymerase chain reaction-high resolution melt technique was used to identify single nucleotide polymorphisms (SNPs) in the para-sodium channel gene. All of the genotyped individuals were mutant, presenting one (n = 7), two (n = 7) or three (n = 9) SNPs previously associated with pyrethroid resistance. Sequencing revealed a novel mutation (F712L), that was found for the first time in R. microplus ticks from South America. This is the first description of mutations associated with pyrethroid resistance in R. microplus from Colombia. The acaricide resistance pattern found in the Arauquita strain is similar to other parts of Colombia.
在哥伦比亚，大量使用化学杀螨剂来控制牛蜱（微小扇头蜱）已导致多重杀螨剂抗性的产生。本研究旨在利用毒理学生物测定法和分子生物学技术，对从哥伦比亚东北部阿劳卡州分离出的蜱虫品系的抗性特征进行表征。在成虫浸泡试验中使用商业杀螨剂来确定其体外药效。溴氰菊酯活性极低（4 - 7.3%），氯氰菊酯和毒死蜱的混合物药效中等（64 - 75.2%），而乙硫磷活性最高（88.5 - 100%）。建立了一个群体（阿劳基塔品系），幼虫浸泡试验证实该品系对溴氰菊酯具有高抗性（241倍），对伊维菌素敏感。使用定量聚合酶链反应 - 高分辨率熔解技术来鉴定对 - 钠通道基因中的单核苷酸多态性（SNP）。所有基因分型个体均为突变型，呈现出一个（n = 7）、两个（n = 7）或三个（n = 9）先前与拟除虫菊酯抗性相关的SNP。测序揭示了一个新的突变（F712L），这是首次在来自南美的微小扇头蜱中发现。这是哥伦比亚微小扇头蜱中与拟除虫菊酯抗性相关的突变的首次描述。在阿劳基塔品系中发现的杀螨剂抗性模式与哥伦比亚其他地区相似。
